几道乘法公式的题目!1.(3a+b)^-(3a-b)^2.79.8^3.解方程:(x-1)(x-2)+(x-2)(x+2)=2(x-3)(x+3)-24.先化简,再求值:(1).y(x+y)+(x+y)(x-y)-x^,其中x=-2,y=二分之一(2).x+y^=50,x+y=10.求xy的值ps:^为平方!希望能回答
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![几道乘法公式的题目!1.(3a+b)^-(3a-b)^2.79.8^3.解方程:(x-1)(x-2)+(x-2)(x+2)=2(x-3)(x+3)-24.先化简,再求值:(1).y(x+y)+(x+y)(x-y)-x^,其中x=-2,y=二分之一(2).x+y^=50,x+y=10.求xy的值ps:^为平方!希望能回答](/uploads/image/z/2113118-62-8.jpg?t=%E5%87%A0%E9%81%93%E4%B9%98%E6%B3%95%E5%85%AC%E5%BC%8F%E7%9A%84%E9%A2%98%E7%9B%AE%211.%283a%2Bb%29%5E-%EF%BC%883a-b%29%5E2.79.8%5E3.%E8%A7%A3%E6%96%B9%E7%A8%8B%EF%BC%9A%28x-1%29%28x-2%29%2B%28x-2%29%EF%BC%88x%2B2%EF%BC%89%3D2%EF%BC%88x-3%EF%BC%89%28x%2B3%29-24.%E5%85%88%E5%8C%96%E7%AE%80%2C%E5%86%8D%E6%B1%82%E5%80%BC%3A%281%29.y%EF%BC%88x%2By%EF%BC%89%2B%28x%2By%29%28x-y%29-x%5E%2C%E5%85%B6%E4%B8%ADx%3D-2%2Cy%3D%E4%BA%8C%E5%88%86%E4%B9%8B%E4%B8%80%282%29.x%2By%5E%3D50%2Cx%2By%3D10.%E6%B1%82xy%E7%9A%84%E5%80%BCps%EF%BC%9A%5E%E4%B8%BA%E5%B9%B3%E6%96%B9%21%E5%B8%8C%E6%9C%9B%E8%83%BD%E5%9B%9E%E7%AD%94)
几道乘法公式的题目!1.(3a+b)^-(3a-b)^2.79.8^3.解方程:(x-1)(x-2)+(x-2)(x+2)=2(x-3)(x+3)-24.先化简,再求值:(1).y(x+y)+(x+y)(x-y)-x^,其中x=-2,y=二分之一(2).x+y^=50,x+y=10.求xy的值ps:^为平方!希望能回答
几道乘法公式的题目!
1.(3a+b)^-(3a-b)^
2.79.8^
3.解方程:(x-1)(x-2)+(x-2)(x+2)=2(x-3)(x+3)-2
4.先化简,再求值:
(1).y(x+y)+(x+y)(x-y)-x^,其中x=-2,y=二分之一
(2).x+y^=50,x+y=10.求xy的值
ps:^为平方!希望能回答的条理清楚!
几道乘法公式的题目!1.(3a+b)^-(3a-b)^2.79.8^3.解方程:(x-1)(x-2)+(x-2)(x+2)=2(x-3)(x+3)-24.先化简,再求值:(1).y(x+y)+(x+y)(x-y)-x^,其中x=-2,y=二分之一(2).x+y^=50,x+y=10.求xy的值ps:^为平方!希望能回答
1.(3a+b)^-(3a-b)^
=(3a+b+3a-b)(3a+b-3a+b)
=6a*2b
=12ab
2.79.8^
=(80-0.2)^
=6400-32+0.04
=6368.04
3.解方程:(x-1)(x-2)+(x-2)(x+2)=2(x-3)(x+3)-2
(x-2)(2x+1)=2x^2-18-2
2x^2-3x-2=2x^2-18-2
3x=18
x=6
4.先化简,再求值:
(1).y(x+y)+(x+y)(x-y)-x^,其中x=-2,y=二分之一
=x(x+y)-x^
=xy
=-1
(2).x^+y^=50,x+y=10.求xy的值
2xy=(x+y)^-(x^2+y^2)
=100-50
=50
xy=25
1.(3a+b)^2-(3a-b)^2=(3a+b+3a-b)*(3a+b-3a+b)^2=(6a)^2*(2b)^2
2.79.8^2=(80-0.2)^2=80*80-2*0.2*80+0.2^2